emerging infectious disease
3 April 2023
emerging and re-emerging disease
basically, anything we’re worried about
- new mutations
- change in environment
- resistant strains
- species jumps (encounter and compatibility: changes via recombination, mutation)
Do we need to understand everything?
- reservoir ecology
- pathogen biology
- human-reservoir interactions
How do we understand? How do we predict?
Batrachochytrium dendrobatidis
Reminders
- fungal pathogen
- most other chytrids are saprophytes, plant pathogens
- B. salamandrivorans: salamander pathogen (more restricted)
- first discoved in poison dart frogs
- caused die-offs in E Australia, Central America, Colorado, California …
- association with high altitude?
- occurred in pristine areas (probably not anthropogenic?)
- pathogenesis via screwed-up osmoregulation
Very confusing …
- some species decline in the absence of Bd
- some species stable in the presence of Bd
(Bd may have been there all along?) - susceptibility:
- ability to bask
- antimicrobial peptides
tipping point hypothesis: in populations all the time, but something happened to increase virulence/reduce tolerance or resistance
climate change/El Niño ?
ultraviolet radiation?
cooler temperatures? (basking etc.)
pesticides?
combination (species × temperature × U/V × pesticide × …)
Pounds et al. (2006): “chytrid-thermal-optimum hypothesis”
Rohr et al. (2008): “numerous other variables, including regional banana and beer production, were better predictors of these extinctions”
Rohr & Raffel (2010)
novel pathogen hypothesis: mutation/speciation + dispersal
- “Out of Africa” hypothesis
- earlier/broader detection in historical specimens: CA/bullfrog, Brazil …
- genomics (challenging!)
- Asian sampling
monkeypox
climate change
- warming
- ‘good’ or ‘bad’ for pathogens?
- vector biology
- extended range
- higher activity?
- changes in seasonality, hydrological cycles
- local landscape change
- hydrology
- land cover (Lyme disease)
- forest cover
- changes in reservoir communities
dilution effect (Keesing & Ostfeld, 2021)
- does increased biodiversity decrease disease?
- variation in reservoir competence
- high-quality hosts decrease with increasing biodiversity
- encounter reduction; host regulation; vector preferences
Kain & Bolker (2019)
Rohr et al. (2020)
prediction
Pulliam & Dushoff (2009)
Walker et al. (2018)
Han et al. (2020)
Carlson et al. (2021)
Evans et al. (2023)
MacDonald & Mordecai (2019)
References
Carlson, C. J., Bevins, S. N., & Schmid, B. V. (2021). Plague risk in the western United States over seven decades of environmental change. bioRxiv, 2021.02.26.433096. https://doi.org/10.1101/2021.02.26.433096
Evans, T. S., Tan, C. W., Aung, O., Phyu, S., Lin, H., Coffey, L. L., Toe, A. T., Aung, P., Aung, T. H., Aung, N. T., Weiss, C. M., Thant, K. Z., Htun, Z. T., Murray, S., Wang, L.-F., Johnson, C. K., & Thu, H. M. (2023). Exposure to diverse sarbecoviruses indicates frequent zoonotic spillover in human communities interacting with wildlife. International Journal of Infectious Diseases, 0(0). https://doi.org/10.1016/j.ijid.2023.02.015
Han, B. A., O’Regan, S. M., Paul Schmidt, J., & Drake, J. M. (2020). Integrating data mining and transmission theory in the ecology of infectious diseases. Ecology Letters, 23(8), 1178–1188. https://doi.org/10.1111/ele.13520
Kain, M. P., & Bolker, B. M. (2019). Predicting West Nile virus transmission in North American bird communities using phylogenetic mixed effects models and eBird citizen science data. Parasites & Vectors, 12(1), 395. https://doi.org/10.1186/s13071-019-3656-8
Keesing, F., & Ostfeld, R. S. (2021). Dilution effects in disease ecology. Ecology Letters, 24(11), 2490–2505. https://doi.org/10.1111/ele.13875
MacDonald, A. J., & Mordecai, E. A. (2019). Amazon deforestation drives malaria transmission, and malaria burden reduces forest clearing. Proceedings of the National Academy of Sciences, 116(44), 22212–22218. https://doi.org/10.1073/pnas.1905315116
Pounds, A. J., Bustamante, M. R., Coloma, L. A., Consuegra, J. A., Fogden, M. P. L., Foster, P. N., La Marca, E., Masters, K. L., Merino-Viteri, A., Puschendorf, R., Ron, S. R., Sánchez-Azofeifa, G. A., Still, C. J., & Young, B. E. (2006). Widespread amphibian extinctions from epidemic disease driven by global warming. Nature, 439(7073), 161–167. https://doi.org/10.1038/nature04246
Pulliam, J. R. C., & Dushoff, J. (2009). Ability to Replicate in the Cytoplasm Predicts Zoonotic Transmission of Livestock Viruses. The Journal of Infectious Diseases, 199(4), 565–568. https://doi.org/10.1086/596510
Rohr, J. R., Civitello, D. J., Halliday, F. W., Hudson, P. J., Lafferty, K. D., Wood, C. L., & Mordecai, E. A. (2020). Towards common ground in the biodiversity–disease debate. Nature Ecology & Evolution, 4(1), 24–33. https://doi.org/10.1038/s41559-019-1060-6
Rohr, J. R., & Raffel, T. R. (2010). Linking global climate and temperature variability to widespread amphibian declines putatively caused by disease. Proceedings of the National Academy of Sciences, 107(18), 8269–8274. https://doi.org/10.1073/pnas.0912883107
Rohr, J. R., Raffel, T. R., Romansic, J. M., McCallum, H., & Hudson, P. J. (2008). Evaluating the links between climate, disease spread, and amphibian declines. Proceedings of the National Academy of Sciences, 105(45), 17436–17441. https://doi.org/10.1073/pnas.0806368105
Walker, J. W., Han, B. A., Ott, I. M., & Drake, J. M. (2018). Transmissibility of emerging viral zoonoses. PLOS ONE, 13(11), e0206926. https://doi.org/10.1371/journal.pone.0206926
Last updated: 2023-04-02 19:40:00.59958